Clothes dryer door

ABSTRACT

The invention relates to a door for closing off a loading opening of a clothes dryer includes a holding device surrounding the edge of a non-opaque pane in a door frame, via a fixing element and/or a part of the holding element arranged on the housing side. A moisture escape-preventing elastic sealing element is mounted in the non-opaque pane area. In order to prevent fluff accumulation in the connection points between the frame and the non-opaque pane, the inventive sealing element is molded to the part of the holding element placed on the housing side and fits the shape of the internal surface of the non-opaque pane with the aid of a lip-shaped ring.

The invention relates to a door for a tumble dryer, for closing a loading opening which is arranged at least approximately vertically in a housing, including a holding device which grips the edge of a glass pane in a door frame, preferably by means of a mounting and/or a housing-side part of the holding device, and a seal of elastic material for preventing the escape of humidity in the region of the holding device of the glass pane.

DE-GM 78 34 776 discloses a door for a washing machine, said door being pivotably linked on one side, wherein the glass pane which bulges in the form of a pot is held in a circular plastic frame by means of a pressure fit. The groove-type connection point between the plastic frame and the installed glass pane is sealed by means of a circular rubber seal which is located in the groove of the plastic frame and into which the glass pane is pressed.

The hermeticity of this clamped joint is essentially dependent on the dimensional accuracy of the assembled components. Compliance with the small tolerances required for this purpose can only be achieved at considerable cost, in particular with regard to the manufacture of the glass pane.

In commonly marketed drying machines, the glass pane is mechanically fixed in a variety of embodiments by means of a holding device which forms the inside of the door frame. The holding ring or pressure ring is fitted into the externally visible mounting ring of the door and is screwed onto this as an assembly. In this case, the pot-like glass pane is positioned between the outer mounting ring and the holding ring. The seal which prevents an escape of humidity is installed between the holding ring and the offset edge ridge of the glass pane; the screw connection of the holding ring with the external frame part (the mounting ring) effects the required press fit of the glass pane.

In the case of the described door, manufacturing-dependent deviations from tolerance in terms of the thickness of the glass pane and its roundness are admittedly compensated by realizing the pressure that must be applied on the seal, in order to ensure the hermeticity of the connection, by means of the screw connection of holding device and mounting ring. However, definitive dimensional accuracy of the assembled door frame is not satisfied in this manner.

The known solution also has the disadvantage that, between the inner edge region of the holding ring and the edge ridge of the glass pane which is shaped inwards in the form of a pot, a niche is formed in which fluff can accumulate over the course of time during operation of the drying machine. The fluff accumulation at the edge of the glass pane is clearly visible externally, thereby considerably compromising the appearance of the transparent loading opening for the observer. The visual impression is also worsened because the fluff accumulation reveals the otherwise unnoticeable manufacturing tolerances of the glass pane, since the volume of the fluff accumulation is dependent on the width and depth of the niche which is formed between the glass pane and the holding ring, and irregularities in the accumulated fluff layer are particularly noticeable to the human eye at the side edges. However, because glass panes have not been used often previously in doors for tumble-dryers, it follows that the described problem has only been rarely visible.

The invention addresses the problem of designing the door of a front-loading tumble-dryer such that the accumulation of fluff in the region of the pressurized sealing of the pot-like glass pane is avoided, while all requirements in terms of the air seal and humidity seal are nonetheless satisfied.

According to the invention, this problem is solved by the seal being molded onto the housing-side part of the holding device and adapting to the contours of the inner surface of the glass pane by virtue of a lip-type ring (claim 1). As a result of the seal extending towards the center of the glass pane by means of a lip-type ring and adapting to the contour of the glass by virtue of its lip, the fluff is given no adhesion allowing it to settle in a region—as it does e.g. in tumble-dryers in the prior art—where it is undisturbed by washing passing over it.

In an embodiment of the invention, the seal features a ring section which is clamped between the housing-side part of the holding device and the edge of the glass pane in an axial direction of the door (claim 2). It is thus possible to effect an improvement of the seal between internal space and surroundings, going beyond the sealing action of the lip-type ring as presented above.

In a further embodiment of the invention, provision is made for the lip-type ring to feature a cross section which is shaped like an acute-angled triangle and, in its acute-angled region, adapts to the contours of the glass pane (claim 3). The tapering of the material thickness in the acute-angled region of the seal ring has the effect that the seal fits closely against the pot-like pane with ease, without any new niches occurring or steps being formed at the outer end where fluff could again accumulate. As a result of using the seal which is designed thus, the intermediate space between the pot-like glass pane and the holding device is completely filled without forming a step at the transition points to the compression ring and the glass pane. Consequently, the accumulation of fluff in the edge region of the glass pane can be permanently avoided, and therefore the glass pane remains clean even in the case of long-term operation of the drying machine (subsequently designated simply as “tumble-dryer”), and the visual impression of someone seeing the loading opening from the front is not negatively affected. The original function of the inventive seal as a sealing element and as means for tolerance compensation is in no way restricted in comparison with the described known seals.

In a further advantageous development of the invention, the seal is integrally connected to the housing-side part (claim 4). In this case, the outer periphery of the ring section features a circular step which abuts the inside of the housing-side part (claim 5). As a result, it is possible both to create a transition-free connection and to reduce the number of individual parts which must be provided in the assembly, in particular if the seal is sprayed onto the housing-side part (claim 6). Manual insertion and positioning of the seal does not apply when assembling the door.

The invention is explained below with reference to the exemplary embodiments illustrated in the drawing, in which:

FIG. 1 shows a frontal view of a tumble-dryer with a door before loading,

FIG. 2 shows a cross section through the holding device region for the glass pane along the intersection line II-II in FIG. 1,

FIG. 3 shows the housing-side part of the door frame together with the seal in the section as per FIG. 2, and

FIG. 4 shows a cross section through the holding device region of the glass pane in a further exemplary embodiment along the intersection line IV-IV in FIG. 1.

A loading opening (not shown) which is closed by a door 3 is located on the front side 2 of the housing 1 of a tumble-dryer as per FIG. 1. For the purpose of opening, the door can be pivoted about a hinge 5 by means of a handle 4. In order to clarify the structure of the door frame 6, it is intersected on the upper side. In the case of the reference sign II-II the intersection line represents the structure illustrated in FIG. 2, and in the case of the reference sign IV-IV the intersection line represents the structure illustrated in FIG. 4.

In the exemplary embodiment according to FIG. 2, the door 3 of the tumble-dryer consists of a frame 6 into which is fitted a glass pane 7 that bulges inwards in the form of a pot towards the internal space of the tumble-dryer. The glass pane 7 can be manufactured from a transparent plastic or from silicate glass. The frame 6 of the door consists of two parts 8 and 9. The decorative ring 8 is the externally visible part of the door frame 6 and is configured according to current aesthetic demands (not indicated in the diagram). A housing-side part 9 which is connected, e.g. screwed, to the decorative ring 8 forms the inner part of the door frame 6.

In order to increase the sturdiness of the door frame 6, the housing-side part 9 and the decorative ring 8 are strengthened by means of molded ribs 10, 11 and ridges. These make the assembled frame 6 highly bend-resistant and warp-resistant. The external dimensions of the frame parts 8, 9 and the molded strengthening ribs 10, 11 in the housing-side part 9 and in the decorative ring 8 complement each other such that the assembly of the frame parts 8, 9 is facilitated and the assembled parts 8, 9 engage with each other in a custom fit.

On the inside, the assembled parts of the frame 6 form a circumferential reception space for the edge ridge 12 of the glass pane 7 which bulges in the form of a pot. The reception space is dimensioned such that sufficient play is present to reliably compensate for manufacturing-dependent deviations from tolerance of the glass pane 7 in terms of its thickness roundness.

A seal 13 preventing the escape of humidity is arranged between the housing-side part 9 and the edge ridge 12 of the glass pane 7. The seal according to the invention is sprayed onto the housing-side part 9 in this embodiment. The technologies for spraying elastic seals are known and will not be further explained at this point.

In accordance with known sealing elements, the inventive seal 13 features two circumferential unbroken bead-form sealing ribs 14 on its side which is oriented towards the edge ridge 12, wherein said sealing ribs 14 fit closely against the edge ridge 12 of the glass pane 7 under pressure in the assembled door frame 6. The escape of humidity from the internal space of the tumble-dryer into the installation space of the machine is reliably prevented by the bead-form sealing ribs 14. The pressure which must be applied for this purpose between the housing-side part 9 and the edge ridge 12 of the glass pane 7 can be generated by screws (not shown) that connect the decorative ring 8 to the housing-side part 9.

Other connection techniques can also be used. For example, the two individual plastic parts 8, 9 which form the door frame 6 can be connected in a positive manner by virtue of the snap-in elements which are molded in the parts. The screw connection has proven advantageous, however, in particular in order to compensate for thickness tolerances of the edge ridge 12 of the glass pane 7.

The sprayed-on lip-type ring 15 grips the inside 17 of the housing-side part 9 by means of a step 16, and has a flush connection to the inside 17 of said housing-side part 9, such that no projecting step is formed at this point. As shown in FIG. 3, that part of the seal which extends inwards approximately horizontally beyond the edge of the housing-side part 9 tails off in an acute angle as a lip-type ring 15. By virtue of its elasticity of material and shape, this acute-angled region 18 of the seal 13 fits tightly against the outer wall of the glass pane 7 when this is assembled. The acute-angled region 18 of the seal 13 prevents the formation of a step, in whose groove-like cavity fluff could settle in such a way that it cannot be reached, at the placement position.

The seal 13 closes the space between the transparent glass pane 7 and the housing-side part 9 and produces a smooth transition between both components. Since the seal 13 does not leave any edges or steps open, in particular at the points of vibration, any long-term accumulation of fluff is impossible. Fluff which arrives in this region with the dry air glides off the glass pane 7 and the seal 13 and is transported with the dry air stream to a fluff filter which is not shown in the drawing. The visual impression of the glass pane at its edge region always remains equally pleasant during continuous operation of the tumble-dryer.

In the case of a door as per FIG. 4, provision is made for a protective pane 19, this being held together with the outer part (decorative ring 8) of the frame 6, in order to further improve the appearance and protect against contact with the pot-like glass pane 7 which can reach temperatures of 90° C. during operation of the tumble-dryer. For this, the decorative ring 8 is provided at its inner edge with a slightly projecting rib 20 and, by means of a ridge 21, supports itself on a spacer ring 22 which maintains a distance between the decorative ring 8 on one side and the housing-side part 9 of the frame 6 and the edge ridge 12 of the glass pane 7 on the other side. A slightly offset edge of the protective pane 19 is positioned in the intermediate space between spacer ring 22 and rib 20. In this case, the decorative ring 8 is held onto a rear section of the housing-side part 9 of the frame 6 by means of a snap-in rib 23.

REFERENCE NUMERALS

-   1 Housing -   2 Front side -   3 Door -   4 Handle -   5 Hinge -   6 Frame -   7 Glass pane -   8 Decorative ring -   9 Housing-side part (of the frame 6) -   10 Ribs (of the decorative ring 8) -   11 Ribs (of the housing-side part 9) -   12 Edge ridge -   13 Seal -   14 Seal ribs -   15 Lip-type ring -   16 Step of the seal -   17 Inside (of the housing-side part) -   18 Acute-angled region -   19 Protective pane -   20 Rib (of the decorative ring) -   21 Ridge (of the decorative ring) -   22 Spacer ring -   23 Snap-in rib -   24 Ring section 

1-6. (canceled)
 7. A door for a tumble dryer, the door comprising: a.) a non-opaque pane; b.) a door frame, the door frame being movable between a closed position in which the door closes off a loading opening of a tumble dryer that is formed in a housing of the tumble dryer and that delimits a substantially vertical plane and an open position in which access can be had through the loading opening to an interior volume of the tumble dryer; c.) a holding device for engaging an edge portion of the non-opaque pane to thereby aid in retaining the non-opaque pane at a predetermined location on the door frame in which the non-opaque pane is centered on a pane axis extending perpendicularly to the substantially vertical plane delimited by the loading opening of the tumble dryer; and d.) a sealing element, the sealing element being formed of elastic material and performing a sealing function generally at the location at which the holding device and the non-opaque pane are in engagement with one another to resist thereat the outward passage of humid air from an interior volume of the tumble dryer, the sealing element having a radially outward section and a lip ring that is radially inwardly of the radially outward section of the sealing element as viewed relative to the pane axis and that substantially conforms to contours of certain portions of the non-opaque pane with which the lip ring is in sealing contact.
 8. The door as claimed in claim 7, wherein the door frame has exterior portions that face away from the housing of the tumble dryer in the closed position of the door frame and the holding device has a housing-facing portion that faces the housing of the tumble dryer in the closed position of the door frame and the radially outward section of the sealing element is compressively engaged between the housing-facing portion of the holding device and the edge portion of the non-opaque pane.
 9. The door as claimed in claim 7, wherein the radially innermost portion of the lip ring is defined by an annular edge formed at the intersection of two surfaces of the lip ring that are at an acute angle to each other such that a radial cross-section of the annular edge of the lip ring of the sealing element resembles an acute-angled triangle,
 10. The door as claimed in claim 7, wherein the sealing element is integrally connected to the housing-facing portion of the holding device.
 11. The door as claimed in claim 9, wherein the radially outward section of the sealing element includes an annular step portion that abuts a radially inward surface of the housing-facing portion of the holding device.
 12. The door as claimed in claim 11, wherein the sealing element is formed via spraying of elastic material onto the housing-facing portion of the holding device. 